• Communications for Statistical Applications and Methods
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• v.28 no.5
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• pp.425-445
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• 2021

A generalization of the log-logistic (LL) distribution called exponentiated log-logistic (ELL) distribution on lines of exponentiated Weibull distribution is considered. In this paper, based on progressive type-II censored samples, we have derived the maximum likelihood estimators and Bayes estimators for three parameters, the survival function and hazard function of the ELL distribution. Then, under the balanced squared error loss (BSEL) and the balanced linex loss (BLEL) functions, their corresponding Bayes estimators are obtained using Lindley's approximation (see Jung and Chung, 2018; Lindley, 1980), Tierney-Kadane approximation (see Tierney and Kadane, 1986) and Markov Chain Monte Carlo methods (see Hastings, 1970; Gelfand and Smith, 1990). Here, to check the convergence of MCMC chains, the Gelman and Rubin diagnostic (see Gelman and Rubin, 1992; Brooks and Gelman, 1997) was used. On the basis of their risks, the performances of their Bayes estimators are compared with maximum likelihood estimators in the simulation studies. In this paper, research supports the conclusion that ELL distribution is an efficient distribution to modeling data in the analysis of survival data. On top of that, Bayes estimators under various loss functions are useful for many estimation problems.

• The Journal of Society for e-Business Studies
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• v.14 no.4
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• pp.299-313
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• 2009

As domestic logistics environment has changed into global logistics, various logistics parties are participating in processing logistics business. Goods is packed into container and delivered to consignee in steps. The goods may be damaged or lost since it has not directly delivered to consignee by single entity during the delivery process. Therefore, all parties want to know the flow of export/import cargos. However, it is very difficult to follow cargo flow consistently delivered from consignor to consignee. Because cargo flow does not be matched up information flow and information systems are based on neither standard business processes nor standard data, which makes it very difficult to associate logistics data among various logistic parties. This paper performs business process modeling for cargo tracking with international standard modeling methodology released by UN/CEFACT. And then, the standard data is defined for cargo tracking business process of unified and integrated business collaboration. The resulting business process model and data model will support international interoperability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.953-954
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• 2012

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.157-165
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• 2016

Among high-tech products, the mobile phone has experienced a rapid rate of innovation and a shortening of its product life cycle. The shortened product life cycle poses major challenges to those involved in the creation of forecasting methods fundamental to strategic management and planning systems. This study examined whether the best model applies to the entire diffusion life span of a mobile phone. Mobile phone sales data from a specific mobile service provider in Korea from March of 2013 to August of 2014 were analyzed to compare the performance of two S-shaped diffusion models and two non-linear regression models, the Gompertz, logistic, Michaelis-Menten, and logarithmic models. The experimental results indicated that the logistic model outperforms the other three models over the fitted region of the diffusion. For forecasting, the logistic model outperformed the Gompertz model for the period prior to diffusion saturation, whereas the Gompertz model was superior after saturation approaches. This analysis may help those estimate the potential mobile phone market size and perform inventory and order management of mobile phones.

• Spatial Information Research
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• v.8 no.1
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• pp.85-99
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• 2000

Accurate information on habitat distribution of protected fauna is essential for the habitat management of Korea, a country with very high development pressure. The objectives of this study were to develop a habitat suitability model of wild boar based on GIS and logistic regression, and to create habitat distribution map, and to prepare the basis for habitat management of our country s endangered and protected species. The modeling process of this restudyarch had following three steps. First, GIS database of environmental factors related to use and availability of wild boar habitat were built. Wild boar locations were collected by Radio-Telemetry and GPS. Second, environmental factors affecting the habitat use and availability of wild boars were identified through chi-square test. Third, habitat suitability model based on logistic regression were developed, and the validity of the model was tested. Finally , habitat assessment map was created by utilizing a rule-based approach. The results of the study were as folos. First , distinct difference in wild boar habitat use by season and habitat types were found, however, no difference in wild boar habiat use by season and habitat types were found , however, ho difference by sex and activity types were found. Second, it was found, through habitat availability analysis, that elevation , aspect , forest type, and forest age were significant natural environmental factors affecting wild boar hatibate selection, but the effects of slope, ridge/valley, water, and solar radiation could not be identified, Finally, the habitat at cutoff value of 0.5. The model validation showed that inside validation site had the classification accuracy of 73.07% for total habitat and 80.00% for cover habitat , and outside validation site had the classification accuracy of 75.00% for total habitat.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.737-748
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• 2010

Glutaminase production in Zygosaccharomyces rouxii by solid-state fermentation (SSF) is detailed. Substrates screening showed best results with oatmeal (OM) and wheatbran (WB). Furthermore, a 1:1 combination of OM:WB gave 0.614 units/gds with artificial sea water as a moistening agent. Evaluation of additional carbon, nitrogen, amino acids, and minerals supplementation was done. A central composite design was employed to investigate the effects of four variables (viz., moisture content, glucose, corn steep liquor, and glutamine) on production. A 4-fold increase in enzyme production was obtained. Studies were undertaken to analyze the time-course model, the microbial growth, and nutrient utilization during SSF. A logistic equation ($R^2$=0.8973), describing the growth model of Z. rouxii, was obtained with maximum values of ${\mu}_m$ and $X_m$ at $0.326h^{-1}$ and 7.35% of dry matter weight loss, respectively. A goodfit model to describe utilization of total carbohydrate ($R^2$=0.9906) and nitrogen concentration ($R^2$=0.9869) with time was obtained. The model was used successfully to predict enzyme production ($R^2$=0.7950).

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.5
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• pp.400-407
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• 2011

The suggested method of previous Son's study dichotomized subjective response data to modeling noise exposure-response. The method used maximum liklihood estimation instead of least square estimation and the noise exposure-response curve of the study was logistic regression analysis result. The method was originated to modeling community response rate such as %HA or %A. It can be useful when the subjective response was investigated based on predicted noise level. It is difficult to measure the single source emitting noise such as railway because various traffic noise sources combined in our life. The suggested method was adopted to model in this study and railway noise-exposure response curves were modeled because the noise level of this area was predicted data. The data of this study was used by previous Ko's paper but he dealt the area as combined noise area and divided the data by dominant noise source. But this study used all data of this area because the annoyance response to railway noise was higher than other noise according to the result of correlation analysis. The trend of the %HA and %A prediction model to train noise of this study is almost same as the model based on measured noise of previous Lim's study although the investigated areas and methods were different.

• Spatial Information Research
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• v.10 no.4
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• pp.501-513
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• 2002

Eurasian otter (Lutra lutra) is one of endangered wildlife species whose population size is declining in Korea. To manage and conserve habitat for Eurasian otter, it is crucial to understand which habitat components affect otter habitat qualities. The objectives of this study were to develop a habitat suitability model of Eurasian otter in Soraksan National Park, to validate the model in Odaesan National Park. The research methods of this study were as follows. First, trace data and characters of Eurasian otter habitat were collected with Geographic Information System (GIS) data and Global Positioning System (GPS) receivers between 2000 and 2002. Second, the habitat use factors were identified as habitat characteristics of Eurasian otter and classified with habitat use and availability analyses. Third, significant factors of habitat model were extracted by Chi-square test. The last, Eurasian Otter Habitat Suitability Model (EOHSM) was employed by logistic regression method. Otter habitat use was positively associated with the reeds and shrubs areas adjacent to streams, the size of boulders, and low human disturbance in Soraksan National Park by EOHSM. This model had a classification accuracy of 74.4% at cutoff value of 0.5. Model validation showed a classification accuracy of 86.6 % at cut off value of 0.5 for otter habitat in Odaesan National Park.

• Journal of the Korea Institute of Building Construction
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• v.17 no.6
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• pp.535-544
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• 2017

This paper analyzes the relations between design errors, prevented by building information modeling (BIM)-based design validation, and their impacts in order to identify critical consideration factors for implementing BIM-based design validation in architecture, engineering, and construction (AEC) projects. More than 800 design errors detected by BIM-based design validation in two BIM-based projects in South Korea are categorized according to their causes (illogical error, discrepancy, and missing item) and work types (structure, architecture, and mechanical, electrical, and plumbing (MEP)). The probabilistic relations among the independent variables, including the causes and work types of design errors, and the dependent variables, including the project delays, cost overruns, low quality, and rework generation that can be caused by these errors, are analyzed using logistic regression. The characteristics of each design error are analyzed by means of face-to-face interviews with practitioners. According to the results, the impacts of design error causes in predicting the probability values of project delays, cost overruns, low quality, and rework generation were statistically meaningful.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1111-1117
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• 2014

Golestan province has a reputation for relatively high incidence rates of gastric cancer in Iran. Along with dietary, lifestyle and environmental influential factors, soil selenium and high levels of pesticide used may exert influence in this region. The present study was designed for modeling the influential predictors on incidence of gastric cancer in Golestan. All registered cases of gastric cancer from March 2009 to March 2010 (49 females and 107 males) were investigated. Data were gathered by both check list and researcher made questionnaire (demographic, clinical and lifestyle characteristics) and analysed using logistic regression. Mean (${\pm}SD$) age at diagnosis was $62.9{\pm}13.8$ years. CIR and ASR of gastric cancer showed 9.16 and 13.9 per 100,000 people, respectively. Based on univariate logistic regression, a history of smoking (OR= 2.076), unwashed hands after defecation (OR= 2.612), history of cancer in relatives (OR= 2.473), history of gastric cancer in first-degree relatives (OR= 2.278), numbers of gastric cancers in first-degree relatives (OR= 2.078), history of X-ray and dye exposure (OR= 2.395), history of CT scan encounter (OR= 2.915), improper food habits (OR= 3.320), specific eating behavior (OR= 0.740), consumption of probable high risk foods (OR= 2.942), charred flesh (OR= 1.945), and animal fat (OR= 2.716) were confirmed as a risk factors. Changes in lifestyle may be expected to increase gastric cancer incidence dramatically in the near future. Therefore, appropriate educational interventions should be designed and implemented by competent authorities.